Development and characterization of the PolyU-1 lunar regolith simulant based on Chang’e-5 returned samples

Leading national space exploration agencies and private enterprises are actively engaged in lunar exploration initiatives to accomplish manned lunar landings and establish permanent lunar bases in the forthcoming years.With limited access to lunar surface materials on Earth,lunar regolith simulants are crucial for lunar exploration research.The Chang’e-5(CE-5)samples have been characterized by state-of-the-art laboratory equipment,providing a unique opportunity to develop a high-quality lunar regolith simulant.We have prepared a high-fidelity PolyU-1 simulant by pulverizing,desiccating,sieving,and blending natural mineral materials on Earth based on key physical,mineral,and chemical characteristics of CE-5 samples.The results showed that the simulant has a high degree of consistency with the CE-5 samples in terms of the particle morphology,mineral and chemical composition.Direct shear tests were conducted on the simulant,and the measured internal friction angle and cohesion values can serve as references for determining the mechanical properties of CE-5 lunar regolith.The PolyU-1 simulant can contribute to experimental studies involving lunar regolith,including the assessment of interaction between rovers and lunar regolith,as well as the development of in-situ resource utilization(ISRU)technologies.

Metallurgical performance evaluation of space-weathered Chang’e-5 lunar soil

Space metallurgy is an interdisciplinary field that combines planetary space science and metallurgical engineering.It involves systematic and theoretical engineering technology for utilizing planetary resources in situ.However,space metallurgy on the Moon is challenging because the lunar surface has experienced space weathering due to the lack of atmosphere and magnetic field,making the mi-crostructure of lunar soil differ from that of minerals on the Earth.In this study,scanning electron microscopy and transmission electron microscopy analyses were performed on Chang’e-5 powder lunar soil samples.The microstructural characteristics of the lunar soil may drastically change its metallurgical performance.The main special structure of lunar soil minerals include the nanophase iron formed by the impact of micrometeorites,the amorphous layer caused by solar wind injection,and radiation tracks modified by high-energy particle rays inside mineral crystals.The nanophase iron presents a wide distribution,which may have a great impact on the electromagnetic prop-erties of lunar soil.Hydrogen ions injected by solar wind may promote the hydrogen reduction process.The widely distributed amorph-ous layer and impact glass can promote the melting and diffusion process of lunar soil.Therefore,although high-energy events on the lun-ar surface transform the lunar soil,they also increase the chemical activity of the lunar soil.This is a property that earth samples and tradi-tional simulated lunar soil lack.The application of space metallurgy requires comprehensive consideration of the unique physical and chemical properties of lunar soil.

Rapid screening of Zr-containing particles from Chang’e-5 lunar soil samples for isotope geochronology:Technical roadmap for future study

New samples returned by China Chang’e-5(CE-5)mission offer an opportunity for studying the lunar geologic longevity,space weathering,and regolith evolution.The age determination of the CE-5 samples was among the first scientific questions to be answered.However,the precious samples,most in the micrometer size range,challenge many traditional analyses on large single crystals of zircon developed for massive bulk samples.Here,we developed a non-destructive rapid screening of individual zirconium-containing particle for isotope geochronology based on a Micro X-ray fluorescence analysis(μXRF).The selected particles were verified via scanning electron microscopy(SEM),3D X-ray microscopy(XRM),and focused ion beam scanning electron microscopy(FIB-SEM)techniques,which showed that zirconium-bearing minerals with several microns were precisely positioned and readily suitable for site-specific isotopic dating by second ion mass spectrometry(SIMS).Such protocol could be also appli-cable in non-destructively screening other types of particles for different scientific purposes.We there-fore proposed a correlative workflow for comprehensively studying the CE-5 lunar samples from single particles on nanometer to atomic scales.Linking various microscopic and spectromicroscopic instru-ments together,this workflow consists of six steps:(1)single-particle selection with non-destructive μXRF technique,(2)2D/3D morphological and structural characterization with a correlative submicron 3D XRM and nanoscale resolution FIB-SEM imaging methods,(3)SEM analysis of the surface morphology and chemistry of the selected particle,(4)a series of microscopic and microbeam analyses(e.g.,SEM,electron probe microanalysis,and SIMS)on the cross-section of the selected particle to obtain structural,mineralogical,chemical,and isotopic features from the micron to nanometer scale,(5)advanced 2D/3D characterization and site-specific sample preparation of thin foil/tip specimens on a microregion of inter-est in the selected particle with FIB-SEM technique,and(6)comprehensive analyses on the FIB-milled specimens at nanometer to atomic scale with synchrotron-based scanning transmission X-ray micro-scopy,analytic transmission electron microscopy,and atom probe tomography.Following this technical roadmap,one can integrate multiple modalities into a uniform frame of multimodal and multiscale cor-related datasets to acquire high-throughput information on the limited or precious terrestrial and extraterrestrial samples.

Latest Scientific Results of China's Lunar and Deep Space Exploration(2022–2024)

China has successfully launched six lunar probes so far.From Chang'E-1 to Chang'E-4,they completed the circling,landing and roving exploration,of which Chang'E-4 was the first landing on the far side of the Moon in human history.Chang'E-5 was launched in December 2020,bringing back 1731 g of lunar soil samples.Through the detailed analysis of the samples,the scientists understand the history of late lunar volcanism,specifically extending lunar volcanism by about 800 million to 1 billion years,and proposed possible mechanisms.In addition,there are many new understandings of space weathering such as meteorite impacts and solar wind radiation on the Moon.China's first Mars exploration mission Tianwen-1 was successfully launched in July 2021.Through the study of scientific data,a number of important scientific achievements have been made in the topography,water environment and shallow surface structure of Mars.This paper introduces the main scientific achievements of Chang'E-4,Chang'E-5 and Tianwen-1 in the past two years,excluding technical and engineering contents.Due to the large number of articles involved,this paper only introduces part of the results.

Development and calibration of the Moon-based EUV camera for Chang'e-3

The process of development and calibration for the first Moon-based ex- treme ultraviolet （EUV） camera to observe Earth＇s plasmasphere is introduced and the design, test and calibration results are presented. The EUV camera is composed of a multilayer film mirror, a thin film filter, a photon-counting imaging detector, a mech- anism that can adjust the direction in two dimensions, a protective cover, an electronic unit and a thermal control unit. The center wavelength of the EUV camera is 30.2 nm with a bandwidth of 4.6nm. The field of view is 14.7° with an angular resolution of 0.08°, and the sensitivity of the camera is 0.11 count s-1 Rayleigh-1. The geomet- ric calibration, the absolute photometric calibration and the relative photometric cal- ibration are carried out under different temperatures before launch to obtain a matrix that can correct geometric distortion and a matrix for relative photometric correction, which are used for in-orbit correction of the images to ensure their accuracy.

Introduction to the TT&C Scheme for Chang’e⁃5 Mission

Chang’e-5 mission is China’s first lunar sample return mission.It contains several new flight phases compared with the previous lunar missions,such as the lunar take-off and orbit insertion phase,the rendezvous and docking phase,etc.Chang’e-5 mission is extremely complicated and full of new challenges.This paper sorts out the characteristics and the difficulties in telemetry,tracking,and command(TT&C)of Chang’e-5 mission.The main technical contribution is a reliable general design of the TT&C system,including the application of X-band TT&C in launch and early orbit phase(LEOP),multiple targets simultaneous TT&C in X-band,lunar surface benchmark calibration,high-precision and rapid orbit trajectory determination for the lunar surface take-off,remote guidance rendezvous and docking,the determination of the initial navigational value for the separation point of the Chang’e-5 orbiter and returner,and the design of the reentry measurement chain.Based on this scheme,a global deep space TT&C network and interplanetary reentry measurement chain have been established for China,and near-continuous TT&C support for China’s first extraterrestrial object sampling and return mission has been realized,ensuring reliable tracking,accurate measurement and accurate control.The global deep space network can provide TT&C support comparable to that of National Aeronautics and Space Administration(NASA)and European Space Agency(ESA)for subsequent lunar and deep space exploration missions.The techniques of rapid trajectory determination of lunar take-off and orbit entry,as well as high precision and remote guidance of lunar orbit rendezvous and docking can lay a technological foundation for the future manned lunar exploration missions and planetary sampling and return missions.

月球样品的中子活化分析技术研究

月球的起源是月球研究的核心问题。月球探测任务返回的数据和样品极大地提高了人类对地月系统的认知,同时也发现了更多未解之谜,亟待未来的探测任务和科学研究来解答。嫦娥五号月壤是我国首次地外天体采集返回的样品,也是继美国和苏联探月采样任务45年后人类再次获得的月球样品。鉴于月球样品的珍贵性和特殊性,利用先进技术开展其全元素含量的非破坏精准分析对于认识月球演化和月球资源就地开发利用具有重要的意义。依托大型核反应研究堆和加速器中子注量率优势,利用中子活化分析技术可实现月球样品中的全元素非破坏分析:1)仪器中子活化分析技术(INAA)可测量Na—U元素之间的60余种元素;2)瞬发γ中子活化分析技术(PGNAA)可补充测量INAA不适合测量的元素如H、B、C、N等;3)中子深度剖面分析技术(NDP)可测量样品近表面(微米级)聚变能源3He的浓度深度分布;4)缓发中子测量技术(DNC)可定量样品中痕量裂变核素如^(235)U和^(239)Pu,并结合INAA可测量238U/235U同位素比值;5)14 MeV快中子活化分析技术(FNAA)可测量INAA和PGNAA不灵敏或不适合测量的元素如O、Si、P等。因此,中子活化分析技术(NAA)可有效解决月球样品中全元素、非破坏和精准测量问题,为我国深空探测珍贵样品研究提供核分析技术支撑。

Analysis of Chang’e-5 lunar core drilling process

Chang’e-5 explorer successfully acquired lunar regolith core samples from depths of greater than 1 m of lunar surface.This study analyzed the lunar core drilling process based on the telemetry data,image information,and returned samples to optimize the sampling device design and enhance the understanding of the lunar regolith.In particular,a prediction method for the projected drilling path and local terrain fitting of drilling dip angle was proposed based on the flight events recorded during the core drilling process and the image information acquired before,during,and after sampling.The results revealed that the drilling dip angle of Chang’e-5 was approximately2.3.,and the deviation of the drilling length and depth was less than 2 mm.For continuous drilling,a fusion method based on telemetry data and image information was applied to determine the demarcation point of drilling with and without the lunar soil.The position of the demarcation point implied that the drilling point remained at approximately 6 mm loose soil,thereby lagging the action of the force response.Additionally,a characteristic parameter comparison method was proposed for the lunar and ground drilling to analyze the status of the lunar soil.Furthermore,the analysis results revealed that the majority of the Chang’e-5 drilling samples were derived from 0–73.8 cm below the lunar surface and few samples were extracted below 73.8 cm,as the drilling encountered several rocky regions.Moreover,the drilling point exhibited two prominent stratification variations at~28.7 cm and~70 cm below the lunar surface.Ultimately,the preliminary relationship between sample dissected position in soft tube and drilling displacement was analyzed.The segmented estimation results can support research on subsurface lunar soil.

胡154井区长4+5段储层非均质性及其对剩余油开发的影响

为提高鄂尔多斯盆地胡154井区油藏剩余油开发效果,从粒度、渗透率、夹层、分层系数等多个参数入手,对长4+5段储层的宏观及微观非均质性进行了探讨。结果表明:受沉积作用影响,长4+5段储层层内非均质性和层间非均质性程度较强,纵向上渗透率值分布差异较大;砂体几何形态以及渗透率在平面上的差异较大,反映长4+5段储层平面非均质性程度很强,其中长4+52小层储层宏观非均质性最强;长4+5段储层孔隙结构较为复杂,微观非均质性很强。储层非均质性对于剩余油开发有较大影响,可采取降压增注、井网加密和深水调剖等措施解决此类问题。

何家集延长组长4+5-长6沉积特征

本文通过野外露头剖面、岩心观察和测井曲线资料,确定了陕北何家集探区长4+5-长6油层组的沉积微相特征,利用测井资料建立测井相,利用多种沉积相的识别标志及特征,进行长4+5-长6油层组沉积相、沉积微相的划分,并进行各小层沉积微相及砂体平面展布规律研究。依据测井曲线综合解释、岩性特征及试油、试采资料,分析石油富集规律。通过以上综合研究,分析沉积微相与石油富集之间的关系,从而对有利含油砂体进行预测。长4+5-长6油层组沉积属于曲流河三角洲沉积体系,主要发育三角洲平原亚相,沉积微相以水下分流河道和分流间湾为主,骨架砂体为水下分流河道,以北东物源方向为主,总体来看砂体的发育完全受控于沉积微相的展布,均呈北东—南西方向条带状展布。长4+5-长6油层组油藏主要分布在三角洲前缘水下分流河道砂体,主要受岩性控制,分布不均匀,属岩性油藏,通过生、储、盖组合综合评价,认为骨架砂体水下分流河道为有利沉积相带。

月球探测器飞越多小天体的拓展任务设计

为充分利用月球探测任务完成后的探测器,提出控制其从环绕月球或地球的轨道出发开展多个小天体飞越探测拓展任务。结合月球探测任务完成后的探测器飞行状态,重点分析了逃逸月球或地球的能量需求,以及小天体飞越探测的其他必要条件,如小天体亮度、星载设备能力约束等。研究了小天体目标确定和转移轨道设计方法,针对小天体目标众多引起的搜索空间和计算量大、多目标序列优化复杂等问题,设计了小天体目标多层择优搜索算法。以嫦娥五号为例,搜索得到了多个可行的小天体飞越探测方案,结果表明在给定约束下可以交会最多5个小天体,包括尺寸较大的小行星12923。研究结论可直接用于嫦娥五号拓展任务,并为后续月球和小天体探测任务提供有益参考和借鉴。

Scheme design of the CHANG＇E-5T1 extended mission

Flight schemes for the CHANG＇E-5T1 extended mission are investigated in this paper.In the flight scheme and trajectory design, the remaining propellant of the CHANG＇E-5T1 mission is utilized. The CHANG＇E-5T1 mission is firstly introduced with feasible flight goals derived based on the terminal trajectory and satellite status. The flight schemes are designed to include a lunar return and the libration points in the Sun-Earth/Moon and Earth-Moon systems, with an emphasis on the Earth-Moon triangle libration point thus far unexplored. Secondly, three schemes are proposed for the CHANG＇E-5T1 extended mission with different flight goals. The direct libration point orbit transfer and injection method is adopted to solve the issue in the transfer trajectory design.Furthermore, an innovative concept is proposed to transfer from the Earth-Moon collinear libration point to the triangle point using the Sun-Earth/Moon libration point. Finally, the merits and drawbacks of the three schemes are discussed in terms of flight time, control energy and frequency, flight distance, and goal value. As a result, the scheme including a lunar return and the Earth-Moon L2 libration point is selected for the CHANG＇E-5T1 extended mission. A flight to the Earth-Moon libration point is achieved, replicating the achievement of the ARTEMIS mission.

Mineral chemistry and 3D tomography of a Chang’E 5 high-Ti basalt:implication for the lunar thermal evolution history

In December 2020, Chang’E-5(CE-5), China’s first lunar sample return mission, successfully collected samples totaling 1731 g from the northern Oceanus Procellarum. The landing site was located in a young mare plain, a great distance from those of Apollo and Luna missions. These young mare basalts bear critical scientific significance as they could shed light on the nature of the lunar interior(composition and structure) as well as the recent volcanism on the Moon. In this article, we investigated a CE-5 basalt sample(CE5 C0000 YJYX065) using a combination of state-of-art techniques, including high resolution X-ray tomographic microscopy(HR-XTM), energy dispersive X-ray spectroscopy(EDS)-based scanning electron microscope(SEM), and electron probe microanalysis(EPMA) to reveal its 3 D petrology and minerology.Our results show that this sample has a fine-to medium-grained subophitic texture, with sparse olivine phenocrysts setting in the groundmass of pyroxene, plagioclase, ilmenite and trace amounts of other phases. It has an extremely high ilmenite modal abundance(17.8 vol%) and contains a significant amount(0.5 vol%) of Ca-phosphate grains. The mineral chemistry is in excellent agreement with that of Apollo and Luna high-Ti basalts. The major phase pyroxenes also display strong chemical zoning with compositions following the trends observed in Apollo high-Ti basalts. Based on current data, we came to the conclusion that CE5 C0000 YJYX065 is a high-Ti mare basalt with a rare earth element(REE) enriched signature. This provides a rigid ground-truth for the geological context at the CE-5 landing site and clarifies the ambiguity inferred from remote sensing surveys.

老年人平衡能力特点及评估

学术背景:平衡能力是人体的一项重要生理机能,在人类生活中有非常重要的意义。特别是老年人平衡能力下降,直接影响老年人独立生活能力,严重的会引起老年人跌倒,诱发其他疾病。目的:总结老年人平衡能力的国内外研究现状,并展望未来老年人平衡能力研究的发展方向。检索策略:应用计算机检索PubMed数据库1990-12/2007-06有关老年人平衡能力方面的文章,检索词"elderly,balance",限定文章语言种类为English,共检索到208篇文章。同时应用计算机检索中国期刊全文数据库、万方数据库1997-12/2007-06的相关文章,检索词"老年人、平衡能力",限定文章语言种类为中文,共检索到85篇文章。对资料进行初审,选取符合研究要求的有关文章找全文。纳入标准:①平衡能力的研究。②老年人平衡特征。③平衡能力评价。④运动干预对平衡能力的研究。排除理由:①较陈旧的文献。②重复研究。文献评价:共19个研究满足全部纳入标准,予以纳入。其中6篇为老年人平衡特征的文献、8篇平衡评价的文献、5篇运动干预老年人平衡影响的文献。资料综合:①平衡能力是人体相关系统功能的集中表现,研究影响平衡能力的前庭系统、视觉系统、躯体感觉、神经系统及肌肉-骨骼等系统功能增龄性的变化趋势,探究导致平衡能力增龄性变化的主要因素是待解决的问题。②平衡测试是定量评定平衡能力的前提,针对老年群体的特殊性,逐步寻求安全、简捷能全面反映其平衡能力的测试方法。③国内专业人员日益提高了对平衡的关注,发表的论文也较多,但由于平衡评定方法不统一,对中国人民平衡能力增龄性变化的研究没有继承性,研究国民的平衡能力增龄性变化是必要的。④众多研究表明,体育锻炼可以延缓平衡能力的衰退。但研究比较分散,运动项目比较单一,探究利于干预的运动项目以及最佳时机是待解决的热点课题。结论:建立一整套适合中国国民平衡能力评价体系,研究国民的平衡能力增龄性变化是十分有必要的,为全民健身活动中的老年人科学地进行健身提供依据。

Positioning reduction in the real-time phase of Chang'E-2 satellite

The precision of VLBI tracking delays and the positioning reduction results during the real-time tracking phase of the Chang'E-2 satellite are statistically analyzed.The application of the positioning reduction to the real-time monitoring of pivotal arcs of the Chang'E-2 satellite is discussed.The technical specifications of the tests of tracking and control systems in X-band are estimated and evaluated via the positioning reduction method.Useful methodology and software are prepared and practical experience in engineering and technology is accumulated for the follow-up lunar and deep space explorations of China.

羟乙基淀粉130/0.4改善大鼠心肌缺血再灌注损伤

目的:观察羟乙基淀粉(HES)130/0.4(万汶)对缺血再灌注(I/R)损伤心肌的干预作用,探讨其可能的作用机制。方法:24只SD大鼠随机均分为4组(n=6):假手术(S)组、缺血再灌注(IR)组、白蛋白-缺血再灌注(A-IR)组、HES-缺血再灌注(H-IR)组。后3组建立在体大鼠心肌I/R模型,分别在缺血25min时股静脉持续泵入生理盐水、5%白蛋白或HES130/0.4,假手术组行开胸手术但不结扎左冠状动脉前降支。再灌注180min处死大鼠,取心肌组织观察病理学改变;处死前颈动脉采血ELISA法测定TNF-α、IL-1β浓度;测定心肌组织NF-κB活性。结果:H-IR组心肌组织损伤病理学改变较IR组、A-IR组减轻。IR组、A-IR组、H-IR组血清TNF-α、IL-1β水平和心肌NF-κB活性明显高于S组(P<0.05),但其中H-IR组血清TNF-α、IL-1β水平及心肌NF-κB活性上升程度不及IR组、A-IR组(P<0.05)。结论:羟乙基淀粉130/0.4能减轻缺血再灌注所致心肌病理损伤,可能与其抑制NF-κB的活性、减少促炎细胞因子的释放有关。

首次在嫦娥五号月壤中鉴定出铁陨石碎片类型

Lunar soil preserves numerous fragments of meteorites impacting on the Moon,providing a unique opportunity to investigate the distribution of the types of projectiles over billions of years.Here we report the first discovery of an iron meteorite fragment from the Chang’e-5 lunar soil,which consists mainly of martensite(quenched from taenite),kamacite,and schreibersite,with a trace of pentlandite.The meteorite fragment is Ni-and P-rich,S-poor,and based on its mineral chemistry and bulk composition,can be classified into the IID-group,a rare and carbonaceous group of iron meteorite originating in the outer Solar System.This meteorite fragment experienced only limited partial melting followed by fast cooling,suggestive of efficient preservation of intact remnants of iron meteorites impacting on the porous lunar regolith.Alternatively,it is a relic of a low-velocity impact of submillimeter-sized metal grains originated from an IID-like iron meteorite.Our observations demonstrate that it is feasible to achieve the type distribution of meteorites impacting on the Moon via systematically analyzing a large number of metal grains separated from lunar soils,thus shedding light on the dynamic evolution of the Solar System.

撞击过程对月表氧逸度的改造:来自嫦娥五号月壤中撞击玻璃珠的启示

Lunar materials are overall more reducing compared with their terrestrial counterparts,but the mechanism remains to be elucidated.In this study,we present a possible explanation for the changes in redox state of the lunar regolith caused by impact events,based on our investigations of the impact glass beads from Chang’e-5 mission.These glass beads contain iron metal grains and show concentration gradients of FeO and K_(2)O(with or without Na_(2)O)from their rims to centers.The compositional profiles exhibit errorfunction-like shapes,which indicates a diffusion-limited mechanism.Our numerical modeling results suggest that the iron metal grains on the surface of the glass beads were generated through the reduction of FeO by elemental K and(or)Na produced during the impact events.Meanwhile,the iron metal grains inside the bead may have formed due to oxygen diffusion driven by redox potential gradients.Furthermore,our study suggests that impact processes intensify the local reducing conditions,as evidenced by the presence of calcium sulfide particles within troilite grains that coexist with iron metal grains on the surface of the glass beads.This study provides insights into the oxygen diffusion kinetics during the formation of iron metal spherules and sheds light on the changes in redox conditions of lunar materials caused by impact events.

基于嫦娥五号月球样品的月壤残余内摩擦角预测

随着人类探月工程的快速发展,月球基地建设以及月表资源开发利用有望更快实现,合理预测月壤工程力学性质对于未来深层次探月工程意义重大,我国嫦娥五号返回月球样品为研究月壤工程力学特性提供了直接的实测材料。然而,月球样品极其珍贵,难以满足传统土工试验测试.为了应对这一科学挑战,本研究从无损分析月球样品颗粒属性入手,使用高精度X-射线μCT扫描、三维白光干涉、原子力显微镜等无损测试手段,分析了不同类型月壤颗粒的三维多尺度形态、弹性力学和摩擦属性等指标.在此基础上,基于颗粒材料宏微观物理力学理论和数值模型尝试预测了嫦娥五号采样处月壤残余内摩擦角。本研究为基于月球样品信息跨尺度分析月壤工程力学性质提供了可行思路。

嫦娥五号月壤中首次发现蒸发沉积成因的蓝辉铜矿

由于缺乏磁场和大气的保护,月球表面持续受到陨石和微陨石的轰击.撞击引起的气化沉积作用是月表典型的改造过程,该过程往往伴随独特矿物相的产生(如纳米金属铁以及铁硅化合物).研究团队通过对嫦娥五号月壤进行细致的扫描电子显微镜观察,在纯铁颗粒以及玻璃质表面发现了具有典型气相沉积特征的含铜组分,进一步通过透射电子显微镜以及电子能量损失谱确认了这些含铜沉积物为蓝辉铜矿这是首次在月壤中发现此类矿物.本研究提供了月表硫化物发生气化沉积的直接证据,揭示了月表撞击过程引起的气相组分迁移及其对月表物质的显著改造效应.同时,嫦娥五号月壤中蓝辉铜矿的发现进一步拓宽了人们对月表复杂矿物组成的认识.